**Exhibit 21.1****SUBSIDIARIES OF AMEREN CORPORATION****AT DECEMBER 31, 2007**    State or JurisdictionNameof Organization   Ameren Corporation Missouri     Ameren Development Company Missouri          Missouri Central Railroad Company Delaware          Gateway Energy Systems, L.C. Missouri               Gateway Energy WGK Project, L.L.C. Missouri     Ameren Energy Resources Company* Illinois          Ameren Energy Development Company** Illinois               Ameren Energy Generating Company Illinois                    Coffeen and Western Railroad Company Illinois               Ameren Energy Marketing Company Illinois               Illinois Materials Supply Co. Illinois               Electric Energy, Inc. (40% interest)*** Illinois                    Midwest Electric Power Inc. Illinois                    Joppa and Eastern Railroad Company Illinois                    Met South, Inc. Illinois                    Massac Enterprises LLC Illinois               AmerenEnergy Medina Valley Cogen, L.L.C. Illinois               Ameren Energy Fuels and Services Company Illinois                    Cowboy Railroad Development Co. L.L.C. Arkansas     Ameren Illinois Transmission Company Illinois     Ameren Services Company Missouri     Central Illinois Public Service Company, d/b/a AmerenCIPS Illinois     CIPSCO Investment Company Illinois          CIPSCO Leasing Company Illinois     CILCORP INC. Illinois          Central Illinois Light Company, d/b/a AmerenCILCO Illinois               AmerenEnergy Resources Generating Company Illinois                    CLC Aircraft Leasing LLC Delaware          QST Enterprises Inc. Illinois               ESE Land Corporation Illinois                    California/Nevada Development L.L.C. Delaware     Energy Risk Assurance Company Vermont          Missouri Energy Risk Assurance Company LLC Missouri     Illinois Power Company, d/b/a AmerenIP Illinois          Illinois Power Securitization Limited Liability Company Delaware               Illinois Power Special Purpose Trust Delaware
 

 
        Union Electric Company, d/b/a AmerenUE Missouri          Electric Energy, Inc. (40% interest)*** Illinois               Midwest Electric Power Inc. Illinois               Joppa and Eastern Railroad Company Illinois               Met South, Inc. Illinois               Massac Enterprises LLC Illinois          Fuelco LLC Delaware          Union Electric Development Corporation**** Missouri      * Eliminated in February 2008 through merger into a newly formed AmerenEnergy Resources Company, LLC (Delaware), which is a directsubsidiary ofAmeren Corporation.** Eliminated in February 2008 through merger into Ameren Energy Resources Company(Illinois), which was subsequently eliminated in February 2008through merger intonewly formed Ameren Energy Resources Company, LLC.*** As of February 29, 2008, 80% interest in Electric Energy, Inc. will be held by newlyformed Ameren Energy Resources Company, LLC.**** Effective January 1, 2008, Union Electric Company issued a dividend ofUnion Electric Development Corporation stock to Ameren Corporation, which causedUnion Electric Development Corporation to become a direct subsidiary of AmerenCorporation.Subsidiaries not included on this list, considered in the aggregate as a single subsidiary, wouldnot constitute significant subsidiary as of December 31, 2007.